The Incident
by Haberdashing
Summary: One-shot set in the Transcendence AU (transcendence-au on tumblr). As Mabel grows severely ill, the twins consider what costs they are willing to pay to stay together.


Ever since the transformation, Dipper had put all the energy he could into protecting his friends and family. Their connection to him put them in danger, as all sorts of foes sought them out to gain power or vengeance from the demon boy, and he was determined to ensure that they would not suffer because of him. Those who dared to mess with Dipper's friends and family, be they humans or demons or something else entirely, soon learned the error of their ways. Nothing would ever, _ever _happen to them- he would make sure of that.

In fact, Dipper was so focused on protecting his loved ones from malevolent forces that he entirely overlooked the more mundane threats that could destroy a human life.

By the time he sensed it, Mabel had already grown pale and thin. But he didn't need to see her to sense that something was terribly wrong with her; he could feel it as soon as he arrived.

"Are you sick?"

"No." But the word came out weakly as the girl thought of the dull aches and inexplicable bruises that had plagued her over the last few weeks.

"…Mabel, I think you need to see a doctor."

And the seriousness of her brother's voice hit home, to the extent that she made a doctor's appointment before even explaining to Dipper why she'd summoned him in the first place. (Not that it had been anything urgent, just a few basic household chores- mostly she had just been looking for an excuse to see him again.)

A series of doctor's visits and needles and phone calls later, and the girl was given a diagnosis, a single word that would change her life forever.

Cancer.

Mabel had cancer.

Everything moved fast after that, much too fast. Life turned into a series of hospital visits, each one longer than the last. Mabel's long, beautiful brown hair was reduced to thin and uneven wisps by the chemotherapy. The nurses grew to know Mabel, and to smile indulgently as she spoke to thin air. The morphine must have really been getting to her, they decided. And none ever made the connection between the girl calling her dead brother's name and the occasional visits from a brown-haired boy her own age.

Despite Mabel's reassurances, Dipper couldn't help but feel that this was all his fault, almost as much as if she had been attacked by a fellow demon after all. He should have known. He should have sensed it earlier, when it was just beginning, before his sister had known that anything was amiss. If only he had been paying attention… if only he had noticed sooner, gotten her to act before it had gotten to this point… if only…

One day, when the pain was worse than ever and all Mabel wanted was to sleep until everything had gone away, she summoned Dipper again. Or rather, Grunkle Stan summoned him for her, as she had grown too weak to make even the simplest of summoning circles, but their great-uncle immediately left the room to give the siblings some privacy, making some excuse about how he had Mystery Shack business to attend to anyway. And Dipper came right over, instinctively taking the shape of the twelve-year-old he had been years ago, because the boy knew now that there was nothing more important than being by his sister's side.

Mabel looked up at her brother as she began to speak, her eyes glistening with half-suppressed tears, her voice just a raspy whisper. "Dipper… am I going to be okay?"

His silence was answer enough.

She stopped bothering to hide her emotions, and a stream of tears began trickling down her thin, pale face. "Is… is there anything you can do?"

The boy considered the question. "Yeah, there is. But I can't just- you know I want to just help you, but I can't just _do_ that, there has to be-"

Mabel rolled her eyes and gave a weak smile. "I know, I know. What's the catch?"

Dipper looked away, staring intently at the beeping heart monitor, knowing exactly how long it would take for that heartbeat to stop if he didn't act soon. But he couldn't look her in the eye, not when giving her this worst of all news, even though he knew that there was no other way. "…I have to take your soul."

The response his sister gave to this grave news was not what the boy had expected. Mabel laughed, a hoarse laugh that descended into coughing, her tears ceasing at once. "That's all?"

"THAT'S ALL?" His voice took on that dark echo that he had been trying to suppress, his hands filled with blue flames, and the wallpaper of the hospital room peeled off the wall and turned into a fine pile of dust on the floor. Dipper closed his eyes and counted to ten as he calmed down. "Mabel, this is serious! I could possess you, I could make you do anything- _anything_! Do you really want that?"

The two locked eyes again, and Mabel grinned, her cheery face a reflection of happier times. "But you wouldn't do anything to hurt me, would you, bro-bro?"

Dipper hesitated, weighing his answer carefully. He would have loved to give an immediate, confident "no." But, much as he tried to think that he was the same person he'd always been, the demon knew that now he was… well, a demon. There was some small part of him that thought pain was hilarious, that got sick pleasure out of screwing over those who summoned him asking for world domination or to settle petty feuds. Like it or not, some small remnant of Bill's personality had come with the dream demon's powers, and Dipper couldn't help but remember the sheer _glee __that Bill had once taken_in using the boy's body as a puppet. That's what he'd be able to do to Mabel now, throughout her entire life, if the slightest whim struck him.

Mabel's voice wavered, losing its sing-song quality, and the smile disappeared from her face. "…would you?"

But this wasn't some random schmuck off the street. This was _Mabel_. The one he'd entered the world with (okay, so Mabel was born five minutes earlier, as she loved to tease him about). The one who'd always been with him, side by side, no matter what challenges they faced. And his heart broke as he saw his sister's eyes widen, for the first time afraid of the demon her brother had become. He'd give anything to make her fear go away, to make his sister smile once more.

"No. No, of course not. _Never_." The words acted to reassure him as much as her, with both their faces breaking out into wide smiles.

"So stop worrying about it, silly!"

Mabel extended her arm, which was ever so slightly shaking. Dipper's hand filled with blue fire as it tightly grasped hers. Her hand was bony and cold to the touch.

And the deal was made.

The color returned to Mabel's face, her hand grew warm once more, her arm stopped shaking. And Dipper could feel his tie to her grow all the stronger as their handshake ended, knew that their connection was on a whole new level now.

"Thank you, Dipper." Mabel's voice was strong now, loud enough to fill that small hospital room, nearly obscuring the dutiful beeping of the heart monitor.

The demon's fingers gently brushed against his sister's hand, and even though his power was growing in leaps and bounds, he felt somehow smaller than ever before. Her eyes were no longer the only ones filled with tears.

"…any time."


End file.
